The present invention relates to an engine-powered industrial vehicle.
A hybrid vehicle equipped with an Eco-mode (an economy mode) for the purpose of improving fuel efficiency has been proposed. By pressing the Eco-mode button, the vehicle is placed in the Eco-mode in which the output torque of the vehicle is restricted for energy saving, which leads to an efficient driving of engine. Such vehicle is disclosed in Japanese Unexamined Patent Application Publication No. 2008-105532.
This Publication discloses a hybrid vehicle in which, in the economy mode, torque is supplemented by the motor while the engine is being driven efficiently so as to maintain the vehicle performance for improvement of fuel efficiency. Unlike such a hybrid vehicle, in an engine type industrial vehicle having no traction motor, supplementing of torque using a motor cannot be performed. Improvement of fuel efficiency in an industrial vehicle, for example in a forklift truck, by restriction of the torque in the Eco-mode is difficult in that the range of the vehicle speed of the forklift truck is smaller as compared with that of an automobile and also that the weight of the vehicle varies significantly according to the load to be handled by the vehicle. If the torque restriction is continued in the Eco-mode, failure in loading operation may occur due to insufficient torque. For example, a vehicle traveling while carrying a heavy load may suffer from shortage of torque due to the heavy load and failure in achieving the maximum vehicle speed.
The present invention is directed to providing an industrial vehicle capable of providing a torque restriction control in an Eco-mode that permits both improvement of fuel efficiency and maximization of vehicle performance.